Heated



March 10, 1964 H. J. M DERMOTT 3 8 HEATED FILAMENT SPINNING PACK FiledFeb. 21, 1961 3/ lllllill J United States Patent 3,123,853 HEATEDFILAMENT SPINNING PACK Henry J. Mclfiermott, (Collingdale, Pa, assiguor,hy mesne assignments, to FMC Corporation, San Jose, Calif, a corporationof Delaware Filed Feb. 21, N61, Ser. No. 90,683 3 Claims. (Cl. 18-h) Thepresent invention relates to the extrusion of artificial filaments, andparticularly to apparatus for melt spinning of thermoplasticfilament-forming materials.

in the conventional melt extrusion processes, comminuted thermoplasticmaterial, as for example in the form of flakes, granules of powders, isdelivered into a heated cylinder fitted with a screw conveyor. Withinthe cylinder the thermoplastic material is advanced and compressed ordensified by the action of the screw conveyor as it is progressivelyheated to a molten or highly plastic state. From the screw conveyor themolten material is delivered into a jet or spinning pack which comprisesfilters, auxiliary devices such as melt distribution plates and aspinneret through which the melt is extruded and shaped into filamentsof des red size.

During the entire extrusion process, and particularly Within the jetpack, the elevated temperature of the molt n filament-forming materialmust be carefully controlled, with little variation in the temperaturebeing permitted. Generally, this is conveniently achieved by jacketingthe jet pack with an electric heater or a tubular coil through which maybe circulated a heated fluid, such as high pressure steam. With theseconventional melt spinning apparatus, repair and adjustment orreplacement of the jet pack, as where a change in denier and/ orfilament count of the production is desired, is complicated by thepresence of the jet pack heater. In some cases disassembly of the heateris required, while in other instan es problems of alignment andadjustment are involved to avoid leakage of the heating fluid and/ or toinsure good heat transfer between the heating means and the jet packitself. Accordingly, an object of the present invention is to provide anew or improved and generally more satisfactory melt spinning apparatus.

Another object is to provide a melt spinning apparatus including a jetpack and a cooperating heating ring having mating surfaces which snuglycontact with each other and provide for good heat conductivity betweenthese parts, yet permit rapid and easy removal of the jet pack withoutdisassembling of the heating ring.

A further object of the invention is the provision of the melt spinningapparatus including a jet pack and a surrounding heating ring which haveconical mating surfaces adapted for wedging with each other to providefor good heat transfer between these parts.

Still another object is to provide a melt spinning apparatus having aspinning pack releasably wedged within a heating ring, with the heatingring being slidably mounted to permit the spinning pack to be easilyadjusted or replaced without removal or disassembly of the heating ringitself.

These and other objects and advantages of the invention will be apparentfrom the following description and accompanying drawing in which:

FTGURE l is a side view of the spinning pack and cooperating heatingring of the present invention, with a portion thereof being shown insection; and

FIGURE 2 is a partial vertical section of the spinning pack illustratingthe assembly of a melt breaker plate and a filter assembly.

in general, the melt spinning apparatus of the present inventionincludes a spinning or jet pack and a surrounding heating ring throughwhich a heated fluid may be circulated. A portion of the outer peripheryof the jet 3,l23,$58 Patented Mar. 10, 1984 pack is provided with agenerally conical surface which mates with a correspondingly shapedsurface provided on the internal periphery of the heating ring. Thesecooperating conical surfaces provide for a wedge connection between theheating ring and the jet pack and thereby assure snug contact and goodheat transfer characteristics between these parts. The heating ringrests on the jet pack during extrusion operations but is slidablysupported by a series of hangers which permit the ring to be lifted awayfrom the jet pack, as when replacement or adjus ment and repair of thepack is desired.

Referring to the accompanying drawing, the melt spinning apparatus ofthe present invention includes a supply conduit it through which moltenfilament-forming material is delivered, as from a screw conveyor, a jetpack 13, and a heating ring 15 which is engaged with the jet pack formaintaining the same at a desired elevated temperature.

The jet pack 13 includes a main body or housing 17 which is formed withan inwardly directed shoulder 19 at one end on which is supported aflange 21 of a conventional spinneret or jet 23. A breaker plate 25 isurged against the spinneret flange 21 by a coupling 27 which is in turnlocked in position by a nut 2h threaded into the housing 17. The nut 29bears against a flange 31 formed on the coupling 2'7 to hold the partsin assembled positions yet is slidable relative to the coupling itselfto minimize twisting thereof as the nut is tig tened. The upper end ofthe breaker plate 25 is provided with a recess as shown at 33 into whichis seated, by pressing, a filter assembly 35, a spacer ring 37, and asplit retainer ring 3-9, as more fully described hereafter. The coupling27 is threaded as shown at 4-1 whereby the jet pack 13 may connect as asingle unit to the supply conduit 11.

On its outer periphery, the jet pack housing 17 is provided with anannular projection 43 which is in the form of a truncated cone. Thesurface 44 of the projection 43 is adapted to wedge with a matingconical surface 45 forming the internal periphery of the heating ringl5. As more fully described hereafter, the heating ring 15 is slidablysupported by a pair of hangers or guide rods 47 which are suspended fromthe supply conduit ll, or other fixed structure, and which are providedwith enlarged heads or flanges 49 at their free ends. It will be notedthat with the parts of the apparatus assembled as shown in FTGURE 1, theheating ring 15 is supported by the jet pack housing 17 so that itsweight serves to urge the conical surfaces 44 and 45 snugly together 1dthereby assists in providing for good heat transfer between these parts.

The heating ring 15 is provided with a spiral passage 51 having inletand outlet openings 53 and 55 respectively at its opposite ends. Steamor other heat transfer fluid is delivered into and removed from thepassage 51 by flexible hoses, not shown, which permit the heating ring15 to be moved relative to its hangers 47 without any obstruction. Thefluid inlet and outlet openings 53 and 55 of the ring 15 are preferablylocated approximately 1 from each other and at substantially to thehangers 47, as measured along a circle concentric with the ring axis, tofacilitate easy access to the hose connections yet minimize any tendencyfor the ring 15 to bind as it is moved along the hangers 4?. From thestandpoint of economy and ease of manufacture, the heating ring 15 ispreferably formed of two separate ring elements 57 and 59 which arewelded or otherwise connected, as shown at 61, after they have beenindividually machine. it will of course be understood that the ring 15may be provided with electrical heating means, in lieu of or incombination with the fluid circulating passage, without departing fromthe spirit and scope of the present invention.

The jet pack 13 is completely assembled outside of the melt spinningapparatus thus minimizing the shut-down period of the apparatus duringjet pack replacement. The jet pack assembly operation is rather simpleand merely involves the positioning of the spinneret 23 and breakerplate 25 within the housing 17 as shown in FIG- URE 1, after which thefilter assembly 35, which includes a plurality of individual filters,the spacer ring 3'7 and the split retaining ring 39 are placed in thebreaker plate recess 33, as shown in FIGURE 2. The coupling 27 is theninserted into the housing 17 and is pressed into contact with the upperedge of the breaker plate 25, as by the use of an arbor press. Duringthis pressing operation the retaining ring 39 is urged completely intothe breaker plate recess 33, compressing the edges of the filters of theassembly 35 into a somewhat solid mass which prevents leakage offilament-forming material at this area. While the above noted parts arepressed together, the nut 29 is threaded into the housing 17 to lock theparts of the pack in fixed positions. As heretofore mentioned, theturning movement of the nut 29 is not imparted to the coupling 27 sothat damage or distortion of the filter assembly 35 is avoided.

During the operation of the melt spinning apparatus, the jet pack 13 andheating ring 15 are wedged together as shown in FIGURE 1. A heated fluidmedium is circulated through the spiral passage 51 in the ring 15 and,by conduction, maintains the jet pack at a desired elevated temperature.The molten filament-forming material passes from the supply conduit 11and through the coupling 27, filter assembly 35, and breaker plate 25where it is divided into separate streams before passing through the jet23.

When it is desired to replace a jet pack 13, the flow of moltenfilament-forming material through the conduit 11 is stopped, after whichthe heating ring 15 is tapped lighly to release the same from theconical projection 43 of the jet pack housing. Once loosened, the ring15 is merely lifted along the hangers 47 while the threaded portion 41of the jet pack 13 is unscrewed from the conduit 11. With the jet packremoved, the heating ring 15 may be then released and comes to rest onthe flanged portions 49 of the hangers 47. A new jet pack 13 isinstalled merely by passing the same upwardly through the heating ring15, whereby the mating surfaces 44 and 45 wedge with each other and thering is lifted from the hanger flanges 4-9. The threaded end 41 of thejet pack coupling 27 is then screwed into the conduit 11 and theapparatus is again in condition for extrusion operations.

The simple and rapid jet pack replacement procedure requires that thespinning apparatus be shut-down for only a short period of time. Equallyimportant is the fact that the operator is required to perform a minimumof manipulative operations on the hot and rather compact spinningapparatus. Further, it will be noted that the heating ring 15 is notdisassembled during this replacement procedure, and that it adjustsitself by gravity to the mating surface of new jet pack to provide forsnug contact and good heat transfer between these parts.

It is to be understood that changes and variations may be made withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

I claim:

1. A melt spinning apparatus including a spinning pack having aspinncret for shaping filament-forming material as it is extrudedtherethrough, heating means encircling said spinning pack and engagingtherewith with a wedging action to maintain the same at a desiredelevated temperature, and means supporting said heating means forslidable movement in an axial direction to permit removal of saidspinning pack.

2. A melt spinning apparatus including a spinning pack having a housingand a spinneret for shaping filamentforming material as it is extrudedtherethrough, said housing having an annular portion of generallyconical configuration projecting from its outer periphery, a heatingring encircling said spinning pack for maintaining the same at a desiredelevated temperature, said heating ring having an internal peripheralsurface corresponding with said annular portion of said spinning packand engaging therewith with a wedging action, and means supporting saidheating ring for sliding movement in an axial direction to permitremoval of said spinning pack.

3. Apparatus as defined in claim 2 wherein said annular projectingportion of said housing is in the form of a truncated cone and whereinsaid heating ring supporting means includes a plurality of fixed guiderods along which said ring is slidable, said rods being enlarged attheir free ends for supporting said ring when said spinning pack isremoved.

References Cited in the file of this patent UNITED STATES PATENTS858,648 Ernst July 2, 1907 906,297 Royle Dec. 8, 1908 1,935,821 SimonsNov. 21, 1933 2,147,081 Beekman Feb. 14, 1939 2,336,159 Bent Dec. 7,1943 2,791,802 Weber May 14, 1957 2,841,821 Phipps July 8, 19582,879,543 McDermott Mar. 31, 1959 2,932,062 Speakman et al. Apr. 12,1960 3,041,048 Heijnis June 26, 1962 FOREIGN PATENTS 779,787 GreatBritain July 24, 1957

1. A MELT SPINNING APPARATUS INCLUDING A SPINNING PACK HAVING ASPINNERET FOR SHAPING FILAMENT-FORMING MATERIAL AS IT IS EXTRUDEDTHERETHROUGH; HEATING MEANS ENCIRCLING SAID SPINNING PACK AND ENGAGINGTHEREWITH WITH A WEDGING ACTION TO MAINTAIN THE SAME AT A DESIREDELEVATED TEMPERATURE, AND MEANS SUPPORTING SAID HEATING MEANS